2y-3x=4, 3y-3x=1
2y-3x=4 (1)
3y-3x=1 (2)
(2)-(1)
3y-2y-3x--3x=1-4
y=-3
sub into (1)
2*-3-3x=4
-6-3x=4
-3x=10
x=-10/3
so
x=-10/3 y=-3
check by subbing into (2)
LHS=3*-3 - 3*-10/3 = -9+10 = 1 = RHS excellent :)
